The present invention concerns a opening with a sheet-metal slide that allows a soot/blower lance to be introduced through a tube cage into a medium-pressure gas-accommodating space and high-pressure gas-accommodating space in a boiler heated by waste heat.
Medium-to-high pressure synthesis-gas coolers and waste-heat heated boilers are employed for example in pressurized coal-gasification plants. Their mutually perpendicular walls are constituted of tube-bar-design. Soot and other solid particles precipitate out of the synthesis gas and onto the inner surface of the walls. Lances are generally employed to blast the deposits away.
There is a separate opening through the tube cage for each lance. Each lance is accommodated in a box, and the gas-accommodating space between the box and the wall is welded gas-tight, sealing the hot-gas side off from the boiler's pressure shell.
The waste heat which is subjected to high pressure on the gas side comprise a boiler, gas-tight welded tube cage with additional tube panels, allowing any perceptible heat to be extracted from the synthesis gas and thereby cooling it. The tube cage and the tube panels are accommodated in a pressure shell. The shell is strong enough to accommodate the internal pressure. The shell and cooling system are mechanically connected.
When it is introduced into the waste heat boiler, the lance extends through the pressure shell and then through the tube cage. The reference points for the lances are the sockets on the shell.
The points where the lances are introduced through the walls of the inner structure are designed as sliding points, because of the prevailing temperature differences and due to the mechanical connection between the jacket and the structure, to allow back-and-forth motion.
Known lance boxes for use in conjunction with openings in the wall of a synthesis-gas cooler are currently being provided by the present applicant for the plant operated by the firm of Ruhrchemie in Oberhauses-Holten in the Ruhr.
These boxes comprise horizontal sheet-metal lance holders and vertical sheet-metal lance guides. The guides are slotted. Between them is a sliding plate with a round opening to accommodate the lance. Welded to the sliding plate is a sleeve that is wider inside than the opening through the slide.
The lance is surrounded inside the sleeve with a ring of packing material. A spacing sleeve is thrust over the packing and applies force to it by way of an annular spring, ensuring a tight seal between the inner and outer gas-accommodating spaces in the cooler.
The slide is unprotected and its inner surface exposed to high heat. The heat can lead to corrosion-derived wear and to temperature-dictated deformation. The slide can jam even though the pipes are kinked inside the opening and clad with a refractory ramming mass.